As the diffusion (second term in equation in REF ) of magnetic field would be a slow process and can be neglected for the astrophysical systems as explained above but, in some cases it is found that the magnetic energy evolved in an enormous amount very quickly (10\(^{26}\)  J energy released in case of a flare eruption ([1]})). Hence even if the magnetic diffusivity is small, the magnetic field gradient may be large enough that the second term in equation REF  can not be neglected. In such magnetic configurations a concentrated plate/sheet of electric current is supposed to be present in between the two opposite magnetic fields. This
current sheet plays an important role for the large and small scale solar eruptions. In the current sheets, the second term \(\eta \nabla ^2 B\)  in equation REF  becomes dominant and the magnetic field diffuse/decay at the center. This decay of magnetic field promote the decrease of the magnetic pressure (\(B^2/2\mu _o\) ) in the central region and the plasma from other regions (above and below) will be sucked into the central part. This motion of fresh magnetic field lines towards the central region gives rise to the reorientation of magnetic field lines called, magnetic reconnection as presented in Figure REF  (bottom panel).
In this way, the complete system pushes against the central part due to the plasma situated in the up and down direction, and the plasma in the central region is squeezed out from two sides (with velocity \(v_0\)  from P and Q in Figure REF ). In Figure REF  (bottom panel), the magnetic reconnection process is explained, where the magnetic field lines ABCD and PQRS are moving inward to the center with velocity \(v_i\) . The inner part of these lines: BC and QR decay away and the parts AB, PQ and CD, RS move outwards to form a new set of lines namely: EXF and GYH respectively. These reconnected magnetic field lines EXF and GYH move away from the reconnection region with velocity \(v_o\) . The current sheet (XY) of length `L' formed in the central part. This scenario of magnetic reconnection has been theoretically well established by [2]}; [3]}; [4]}.
The heat generated due to reconnection can raise the temperature of the plasma, like in case of the solar corona. It is believed that magnetic reconnection takes place in the coronal loops and increase the temperature to million degrees and responsible for violent solar eruptions.
